In recent years, there has been a computer system in which an imaging device connected with a public line network, etc., takes an image such as a still or moving image of a target object and transmits the taken image to a terminal device that exists in a remote place. In such a computer system, whether or not the object is imaged at an appropriate angle depends on the angle of the imaging device at the time of imaging. For example, if an object is to be imaged from the horizontal direction but the imaging device actually turns to a completely different direction, the computer system should turn the camera to the horizontal direction. Especially, if the imaging device is a moving vehicle such a drone, the imaging device hardly adjusts the angle of the camera when imaging an object. This is because the angle formed by the camera to a horizontal line on the object is changed at every imaging.
As such a computer system, the constitution that superimposes an object for calibration on an image taken by an imaging device attached to a moving vehicle and calibrates the position of the imaging device based on the movement distance and the rotation angle of the object for calibration is disclosed (refer to Patent Document 1).